Richard Schilling

Varicose Veins in Women Cotton Workers. An Epidemiological Study in England and Egypt

The prevalence of varicose veins was studied in 504 women cotton workers in England and 467 in Egypt, by a standardized questionary and a specially developed method of examination. The English mill population showed a much higher prevalence of varicose veins than the Egyptian, probably owing to environmental rather than ethnic reasons. Among the European women the prevalence of varicose veins was significantly related to age, parity, body weight, type of corsetry, and occupation—that is, whether or not they stood at their work. After standardizing for the other variables there was a statistically significant excess of varicose veins in women wearing corsets and roll-ons compared with those wearing less-constrictive garments. After a similar standardization a significant excess was found in women who stood at their work compared with those whose jobs entailed walking or sitting.

Diurnal Variation in Ventilatory Capacity: An Epidemiological Study of Cotton and other Factory Workers employed on Shift Work

The change in F.E.V.0·75 during a working shift was studied in a random sample of 473 men employed in three cotton mills in The Netherlands working a three-shift system. Results were also obtained for 198 men, not exposed to industrial dust, who were working in a biscuit factory and two textile factories in the same area. The men were seen only during the shift on which they were working at the time of the study. Men with byssinosis gave a typical picture of the effects of cotton dust on susceptible workers: a generally low F.E.V. with a marked reduction during the shift; –0·16 l. on the early morning shift, and –0·25 l. and –0·33 l. respectively on the afternoon and night shifts. Men without byssinosis in the card and blow rooms showed mean changes in F.E.V. during the shift similar to those of men working in the spinning room: a slight rise in the early morning shift of +0·02 l. followed by a fall in both afternoon and night shifts in the region of –0·10 litres. This pattern of change was also found among the workers in the non-dusty factories. The rise in the early shift cannot be explained by the clearing of mucus from the air passages; cotton workers without respiratory symptoms and men in the non-dusty factories who did not produce sputum still showed an increase in F.E.V. during the early shift, though less marked than that of men with respiratory symptoms or who produced phlegm. The evidence suggests that a diurnal variation in lung function exists and should be taken into consideration both in epidemiological studies and when ventilatory capacity tests are used in periodic medical examinations.

Cigarette smoking, occupational dust exposure, and ventilatory capacity.

Among older men who had been exposed for many years to hemp dust in industry, the relations between ventilatory capacity (as measured by FEV1.0) and cigarette-smoking habits appeared to be affected by a process of self-selection. Active 50 to 69-year-old, moderate to heavy smokers had a significantly higher FEV1.0 than non-smokers or light smokers. Of all men in this age group 26% were ex-smokers, with a low mean FEV1.0. Hemp workers of all smoking categories had a low FEV1.0 in comparison to similar controls. The chronic effect of hemp-dust exposure on FEV1.0 appears to be a main factor in determining who gave up smoking (ie, those who were affected by long-term hemp-dust exposure) and who still smoked. In epidemiological surveys, the relations between lung function results and smoking habits may be contrary to expectation if effects of concurrent exposures to other inhaled noxious agents influence the smoking habits of the subjects.

Cardiovascular Disease in Cotton Workers : Part I.

Since 1891 the Registrar General for England and Walds has recorded high death rates from cardiovascular diseases among cotton workers. Although the health of the cotton worker has been the subject of numerous investigations, there is no other evidence of either excessive mortality or morbidity from cardiovascular disease in the cotton trades. In this paper we attempt to elucidate this problem by a further analysis of the Registrar Generals evidence. In another paper the results of a detailed clinical examination ofmore than 300 men employed in the cotton textile mills of Lancashire will be described. A brief description of the processes used in preparing and spinning raw cotton must be given, so that the terms used to define occupational groups can be understood. Fine cotton dust has been suggested as the cause of this high cardiovascular mortality and the degree of exposure to dust of the different groups of workers will therefore also be discussed.

A study of rope workers exposed to hemp and flax.

Smith, G. F., Coles, G. V., Schilling, R. S. F., and Walford, Joan (1969).Brit. J. industr. Med.,26, 109-114. A study of rope workers exposed to hemp and flax. Respiratory symptoms and ventilatory capacities were studied in 54 men and 22 women exposed to the mixed dusts of hemp and flax in an English rope factory. The preparers and most of the spinners were exposed on average to concentrations of 1·7 mg./m.3 total dust and 0·5 mg./m.3 fine dust. Those employed on subsequent processes had lower exposures at concentrations of 0·5 mg./m.3 total dust and 0·1 mg./m.3 fine dust. Six men, all in the high exposure group, had symptoms of byssinosis. After adjustment for age and standing height there was no statistically significant difference in the forced expiratory volume (F.E.V.1·0) between those in high dust concentrations and those in low concentrations; neither was there a significant difference between the ventilatory capacities of men with and without byssinosis. This study shows that byssinosis is an occupational hazard confined to male workers in this factory. It does not appear to be a very serious problem and will diminish with the increasing use of synthetic materials instead of natural fibres.

STUDY OF RESPIRATORY SYMPTOMS AND VENTILATORY CAPACITIES AMONG ROPE WORKERS

In a rope works handling manila, sisal, and St. Helena hemps, the prevalence of respiratory symptoms and the change in forced expiratory volume (F.E.V.1·0) during the work shift were studied in a group of 41 women and 41 men who represented 93% of the population at risk. Dust concentrations, measured with a modified Hexhlet, ranged from 0·11 to 4·51 mg./m.3 for total dust and 0·02 to 1·46 mg./m.3 for fine dust. The highest concentrations were found in the preparing rooms, in which the workers, all of whom were women, showed on the average a fall in ventilatory capacity during the shift. The workers in the rope walk, all of whom were men, showed a rise in ventilatory capacity during the shift. The difference between the men and women was statistically significant (p < 0·05). No worker gave a characteristic history of byssinosis, although nine women complained of chest tightness associated with their work. Undue breathlessness on exertion and persistent cough and phlegm were also more common among the women, but they were on the average 18 years older than the men. When the ventilatory capacities and the prevalence of respiratory symptoms of women rope workers were compared with those of a group of women employed elsewhere in the dockyard, the only significant difference was that the rope workers had more chest tightness associated with their work (p < 0·02). Exposure of volunteers to St. Helena hemp, which is apparently the most likely of the hard hemps to give rise to respiratory symptoms, caused only a slight fall in ventilatory capacity and a small rise in airways resistance. A sample of St. Helena hemp assayed on guinea-pig ileum had only a relatively small degree of contractor activity. The evidence suggests that the dusts of hard hemps do not cause byssinosis under the conditions in this factory. However, the irritant nature of the dust indicates the need to prevent total dust levels exceeding about 2 mg./m.3.

Developments in Occupational Health

Publisher Summary This chapter discusses developments in occupational health. There is a wide variation in the standards of occupational health practice and research in different countries. This brief historical review indicates the factors that appear to be most significant in influencing national policies—humanity of a society, its wealth, the social status of the worker, his/her political organization, and his/her representation in government. Standards are dictated more by the attitudes of management than by statutes. An important factor is the extent to which employers are aware of the economic advantages of providing for the health and safety of their employees. The more serious effects on health that followed the Industrial Revolution were not directly occupational in origin. Family life was disrupted when men moved into new industrial areas, leaving their families behind. This situation encouraged alcoholism and prostitution. There were also epidemics from overcrowding in unsanitary conditions, malnutrition as a result of the change from rural to urban life, and the poverty that followed unemployment caused by fluctuations in the economy.

Pernicious anaemia in the textile industry.

The objective was to examine whether the observed excess mortality from anaemia in textile and clothing workers was associated with any specific anaemia type or occupational activity. The design was a death certificate based case-control study of textile and clothing workers who died in England and Wales in the years surrounding the decennial censuses of 1961, 1971, and 1981. The main outcome measures were type of anaemia, place of residence, place of birth, and occupation. The frequency of the different types of anaemia in textile and clothing workers differed from that of England and Wales with relatively more deaths from pernicious anaemia than in the country as a whole (74 observed v 55 expected deaths). Within the industry, those whose death was attributed to pernicious anaemia were more than twice as likely as other textile and clothing workers to have worked in textile mills (odds ratio = 2.4, 95% confidence interval 1.4-4.2). These results could not be explained by age, sex, place of residence, or place of birth, and review of the death certificates did not suggest that pernicious anaemia as a cause of death had been recorded in error. Historical support for the finding was found in the Registrar Generals 1931 decennial supplement on occupational mortality, in which the standardised mortality ratio from pernicious anaemia in male textile mill workers was estimated to be twice that of the general population. In conclusion, occupational factors, specifically work in textile mills, could be implicated in the pathogenesis of pernicious anaemia. The aetiology of this disease is not well understood and further study of pernicious anaemia in textile mill workers is required.

Education in occupational health.

Publisher Summary This chapter discusses training and education in occupational health. An academic course in occupational medicine is an important part of specialist training, and its content is markedly similar in different countries. The main topics covered are history and legislation, aims and functions of occupational health services, occupational diseases, work physiology, psychology and toxicology, the measurement and control of the physical environment, ergonomics, statistics, epidemiology, and practical instruction. These include attendance at clinics, factories, and rehabilitation and research centers. There is also a need for short intensive courses to introduce the basic principles of occupational health practice to part-time physicians, who in many countries constitute the majority of doctors in this field of medicine. Such training may be provided through weekend courses, seminars, lectures on tapes with slides, and films. The demand for postgraduate training in occupational hygiene is growing rapidly but is still not as great as that for occupational medicine. The courses aim to teach methods of investigating, evaluating, and controlling environmental hazards. A part of the course is common for both physicians and hygienists. Such combined teaching presents difficulties of organization; however, there are many advantages because with student participation, the viewpoints of both disciplines can be freely expressed and physicians and hygienists can gain a better understanding of their respective roles.